Elastic steel band for sun cap or hat and method and apparatus for manufacturing the same

ABSTRACT

Disclosed herein are an elastic steel band, which is wound over one revolution (angle of over 360°) when a sun cap or a hat is not worn, whereby keeping and portability characteristics of the sun cap or hat are improved, and method and apparatus for manufacturing the same. According to the present invention, the method of manufacturing the elastic steel band includes a material preparation step, a press work step of forming a unit work pieces, a rolling step of rolling the unit work piece 1.5 revolution to less than 3 revolutions, and an unfolding step of bending both ends of the rolled half-finished work piece in an opposite direction to the rolling direction, thus forming unfolded units at both ends of the elastic steel band.

BACKGROUND

1. Field of the Invention

The present invention relates to a band for a sun cap or a hat, which elastically comes in contact with the head to support the sun cap or the hat. More specifically, the present invention relates to an elastic steel band, which is wound over 1 revolution (360°) when the sun cap or the hat is not worn, whereby keeping and portability characteristics of the sun cap or hat are improved, and method and apparatus for manufacturing the same.

2. Discussion of Related Art

In doing a variety of meetings, such as a picnic party and an athletic meeting, and a variety of outdoor activities, such as outdoor work and sport viewing, a hat or a sun cap has been widely used.

The conventional sun cap, however, comes in direct contact with the head, when being put on, so that a band element to support the sun cap is rolled in a circle shape of a diameter, which is a little smaller than the size of a common tofu. Such a diameter is designed to give a support force of a level, which can support the sun cap, when the sun cap is worn. Therefore, this diameter is substantially the same as a state where the hat is fully opened (state where the sun cap is worn). Accordingly, it is inconvenient to carry and keep the hat having such a large diameter, which makes a user inconvenient.

More particularly, since the sun cap is designed to protect a wearer from a strong direct ray of light, there is no need for wearing such a sun cap at places such as the room and the shade of a tree. Thus, if the sun cap has to be worn or took off frequently in such places, it will make a user inconvenient in terms of portability. Also, there is a problem of loss.

Therefore, there is a need for a sun cap of a structure in which the volume is reduced when being not worn, and distribution, keeping and portability characteristics are thus improved, without degrading the unique function and wearing property of the sun cap.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an elastic steel band, which is mounted in a sun cap or a hat and is wound over one revolution (angle of over 360°) when the sun cap or the hat is not worn, whereby the volume of the sun cap or the hat is significantly reduced when being not worn, and distribution, keeping and portability characteristics can be thus improved, and method and apparatus for manufacturing the same.

To achieve the above object, according to the present invention, there is provided an elastic steel band, which is wound over 1 revolution (360°) when a sun cap is not worn, and method of manufacturing the same. This method includes a press work step in which an elastic steel band material is cut into given size and shape and sun cap visor slots are perforated, a step in which an unit work piece is rolled over 1.5 revolutions (540°) to less than 3 revolutions (1080°), and a step in which both ends of the rolled steel band are rewound in a direction opposite to the rolling direction, thus forming unfolded units at both sides of the elastic steel band.

Furthermore, according to the present invention, there is provided an elastic steel band rolling apparatus for rolling an elastic steel band material, which is combined with a flexible visor unit of a sun cap or a hat, and is wound over 1 revolution (360°) when the sun cap or hat is not worn. The apparatus includes a driving unit, a power transmission unit for transferring power from the driving unit, first and second rollers which are driven by the power transmission unit, a rolling shaft disposed on the first and second rollers with it coming in contact with the first and second rollers at a location between the first and second rollers, wherein the rolling shaft transfers and rolls the unit work piece between it and the first and second rollers in cooperation with the first and second rollers, a supply unit for supplying a unit work piece, and a discharge unit for discharging the rolled elastic steel band. In this time, the first and second rollers include elastic drums which are brought into contact with the rolling shaft in order to form an interaction force for rolling the unit work piece from 1.5 revolutions to 3 revolutions. The unit work piece is rolled from 1.5 revolutions to 3 revolutions by means of an interaction force between the elastic drums of the first and second rollers and the rolling shaft, while moving from the supply unit sequentially between the elastic drum of the first roller and the rolling shaft and between the elastic drum of the second roller and the rolling shaft. The elastic drums are preferably urethane drums.

Furthermore, according to the present invention, there is provided an elastic steel band, which is combined with a flexible visor unit of a sun cap or a hat and is wound over 1 revolution (360°) when the cap or hat is not worn, thus reducing the volume. The elastic steel band for the sun cap or the hat includes a winding unit of over 1 revolution (360°) at the center thereof, and unfolded units at both ends thereof. The elastic steel band is formed using an elastic steel material, which gives the elasticity enough to wind the flexible visor unit over 1 revolution (360°) when the cap or hat is not worn, if the elastic steel band is combined with the flexible visor unit. The elastic steel preferably has a sufficient elasticity and rigidity, which can provide a sense of wearing in spite of an elastic force applied to the head when the cap or hat is worn, and can withstand hysteresis caused by a winding force and repetition stress when the cap or hat is not worn. It is preferred that the elastic steel is formed using elastic stainless steel (STS#301-EH).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an elastic steel band according to the present invention;

FIG. 2 a is a perspective view illustrating a sun cap to which the elastic steel band according to the present invention is attached;

FIG. 2 b is a perspective view illustrating a sun cap to which the elastic steel band according to another embodiment of the present invention is attached;

FIG. 3 is a flowchart illustrating process steps for embodying a method of manufacturing an elastic steel band according to the present invention;

FIG. 4 is a perspective view illustrating an unit work piece for manufacturing the elastic steel band according to the present invention;

FIG. 5 is a perspective view illustrating the construction of an elastic steel band rolling apparatus for manufacturing the elastic steel band according to the present invention;

FIG. 6 is a dismantled view illustrating the elastic steel band rolling apparatus according to the present invention;

FIG. 7 is a lateral view illustrating the elastic steel band rolling apparatus according to the present invention;

FIG. 8 is a lateral view illustrating the elastic steel band rolling apparatus according to the present invention;

FIG. 9 is a cross-sectional view showing the construction of a rolling unit of the elastic steel band rolling apparatus according to the present invention; and

FIG. 10 illustrates a half-finished work piece that is machined by the elastic steel band rolling apparatus according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Now the preferred embodiments according to the present invention will be described with reference to the accompanying drawings. Since preferred embodiments are provided for the purpose that the ordinary skilled in the art are able to understand the present invention, they may be modified in various manners and the scope of the present invention is not limited by the preferred embodiments described later.

FIG. 1 is a perspective view illustrating an elastic steel band 10, which is manufactured according to an apparatus and method in accordance with an embodiment of the present invention.

Referring to FIG. 1, the elastic steel band 10 includes a winding unit 18 which can be wound one or more revolution (over 360°), an unfolded units 14 corresponding to about ¼ of a total length from both ends of the winding unit, slots 16 into which a flexible sun cap visor unit 22 (see FIG. 2), and a round elements 12.

In the elastic steel band 10 according to the present invention, for example, with it being coated with an outer texture cover, a coupling member 24 of the flexible sun cap visor unit 22, which is usually used, is inserted into the slots 16, thus producing a finished sun cap 2. When the hat is not worn, the sun cap visor unit keep wound over 1 revolution (over 360°) due to the elasticity of the elastic steel band 10 and the flexibility of the flexible sun cap visor unit 22, as shown in FIG. 2. Accordingly, distribution, keeping and portability can be improved and accompanying cost can be thus reduced.

In FIG. 1, the winding unit 18 of the elastic steel band 10 serves to reduce the volume of the sun cap 20, when the hat is not worn and also to improve distribution, keeping and portability. The unfolded units 14 at both ends of the elastic steel band 10 serves to prevent stress applied to the head from being concentrated on one point so that stress is distributed over a wide area, when the sun cap is worn. Thus, a feeling of wearing and stability of the support can be improved.

Furthermore, the elastic steel band 10 of the present invention is fabricated using stainless steel (for example, STS#301-EH), which is strong against moisture and salt, while having rigidity and elasticity sufficient to withstand hysteresis due to frequent attachment and detachment of the sun cap.

The aforementioned STS#301-EH stainless steel, which is particularly suitable for the elastic steel band according to the present invention, is a kind of austenitic stainless steel that constitutes the main current of the stainless steel, which essentially comprises Ni and Cr, and a small amount of C. It has been used in the fields that require hardness, toughness and elasticity properties.

Furthermore, the elastic steel band of the present invention is preferably formed to have a given dimension, which can prevent the head from being applied with excessive pressure when the sun cap is worn, while providing a shape in which the elastic steel band is wound over 1 revolution when the hat is not worn, considering the material, rigidity and design of the flexible sun cap visor unit.

A method of manufacturing the elastic steel band according to the present invention will now be described in detail with reference to FIG. 3.

The method of manufacturing the elastic steel band according to the present invention includes a material preparation step (S100), a press work step (S200) of cutting a material into unit work pieces (see 10′ in FIG. 4) of a size and shape corresponding to the dimension of the final elastic steel band, a rolling step (S300) of rolling the unit work pieces over 1.5 revolutions (540°) to less than 3 revolutions (1080°), and an unfolding step (S400) of forming the unfolded units 14 at both ends of the elastic steel band by bending both ends of the rolled half-finished work piece (see 10″ in FIG. 10) in a direction opposite to the rolling direction.

The material preparation step (S100) includes the process of continuously shaping a proper material, such as elastic stainless steel (for example, STS#301-EH), into a strip shape (S102), and the process of rounding consecutive strip edges in order to prevent friction damage with the outer cover of a texture or a sharp portion from making the head unpleasant when a sun cap is worn (S104). The rounding process can be carried out after the press work step (S200). The material preparation step (S100) may further include an annealing process (S106) depending on a characteristic of a material, a necessary strength and elasticity condition. Information on annealing of a metal material, and variation in strength and elasticity accordingly is well known in the art. Thus, description on it will be omitted for simplicity.

The press work step (S200) includes the process of cutting a material into the length corresponding to the length of a final elastic steel band (S202), and the process of punching the slots to which the sun cap visor unit is coupled. The length and shape of the unit work piece 10′, the location of the flexible sun cap visor slots 16, etc. can vary depending on the material, size, shape, etc. of the sun cap visor unit 22, which is finally assembled. Moreover, when the material is cut in the press work step (S200), the round elements 12 are formed at both ends of the elastic steel band (S206) in order to improve the insertion property into a final texture cover, reduce abrupt friction with the texture cover, and remove inconvenience which will be given to the head when the sun cap is worn. This press work step (S200) can be performed in a single step or a number of steps by using various press machines and punchers, which are widely known in the art. In terms of the shortage of the work process and the reduction of cost, however, this press work step (S200) is preferably carried out through a single process of performing cutting and punching at the same time by using upper and lower dies corresponding to the shape of the unit work piece 10′ shown in FIG. 4. The shape of the dies corresponding to the shape of the unit work piece 10′, the construction of the press machine, and detailed work, parameters are well known in the art. Description on them will be omitted.

The rolling step (S300) is performed by a rolling apparatus, which will be described in detail with reference to FIGS. 5 to 9. In the rolling step (S300), the unit work pieces 10′ are rolled from 1.5 revolutions to 3 revolutions. This is for assigning the shape corresponding to the final elastic steel band as shown in FIG. 1, which is suitable for comprising conflicting parameters such as a proper elastic force, and improved keeping and portability after the unfolding step (S400) is performed. In the concrete, the higher the rolling angle and the greater the strength of an elastic steel band material, the greater the winding force. Accordingly, when the sun cap is worn, the volume is significantly reduced to improve keeping and portability characteristics. However, a sense of oppression applied to the head when the sun cap is worn also increases, which results in increased inconvenience. Therefore, a central winding unit is preferably wound one or more revolutions (360°), which compromises conflicting factors such as a sense of wearing and portability. Further, in order to implement the shape shown in FIG. 1 having the unfolded units for improving a sense of wearing, rolling from 1.5 revolutions to 3 or more revolutions is preferably performed.

The inventors of the present invention repeated a number of tests on STS#301-EH elastic stainless steel. As a result of the test, it was found that a shape in which about ½ of a total length of the elastic steel band center forms a winding unit of over 1 revolution and is gradually transferred to both the unfolded units satisfies a sense of wearing and portability at the same time. Therefore, in the case of a rolling of less than 1.5 revolutions, it is difficult to form the unfolded units. In the case of a rolling of over 3 revolutions, an excessive sense of oppression is given to the head, thus degrading a sense of wearing. Furthermore, it was found that the keeping and portability characteristics are not significantly improved in that the number of winding is not significantly increased because of a combined effect of the shape of the unfolded units and the flexible sun cap visor unit, rigidity, etc.

Moreover, a plurality of experiments shows that an optimum result was obtained when a rolling of about 2 revolutions (720°) is performed.

Consequently, the rolling step (S300) preferably includes rolling the unit work pieces 10′ from 1.5 revolutions to 3 revolutions, more preferably about 2 revolutions. The shape of the rolled half-finished work piece 10″ is shown in FIG. 10.

Detailed work steps of an additional rolling will be described in detail with reference to the structure of the rolling apparatus, which will be described with reference to FIGS. 5 to 9.

Finally, in the unfolding step (S400), both ends of the rolled half-finished work piece 10″ are bent in a direction opposite to the rolling direction, so that some portions of both ends are unfolded.

The unfolded units 14 are located at the sides of the head when the sun cap is worn and come in contact with the head over a wide range, thus preventing concentration of stress and improving a sense of wearing. That is, in the shape of the final elastic steel band 10 shown in FIG. 1, the central winding unit 18 is located at the front of the head having a large curve, i.e., the forehand. The unfolded units come in contact with the sides of the head, which are relatively flat. Thus, a large winding angle of the winding unit, a substantially flat winding angle of the unfolded units, and a gradual transmission portion from the winding unit to the unfolded units provide an optimum adaptability for the shape of the head when the sun cap is worn, thereby improving a sense of wearing and support performance.

In this time, in a state where portions corresponding to a given length from both ends of the half-finished work piece 10″ are fixed, the winding force is applied in a direction opposite to the rolling direction. Thus, the unfolded units and the transmission portion are formed at the same time. The degree of the winding in the direction opposite to the rolling direction for this purpose may vary a characteristic of a material and a detailed design of a work piece. In the elastic steel band according to the present invention, a length including the transmission portion and the unfolded units is preferably about ¼ of a total length of the elastic steel band 10. It is preferred that the final elastic steel band has a shape which is a little inwardly wound because of the transmission portion from the winding unit to the unfolded units.

The construction of the rolling apparatus according to the present invention will now be described in detail.

FIGS. 5 to 9 show the rolling apparatus for performing the rolling step (S300) according to the present invention.

Referring to FIGS. 5 to 9, the rolling apparatus 60 for manufacturing the elastic steel band 10 according to the present invention includes a driving unit 30, power transmission units 32, 56, 44, 46 and 48, first and second rollers 38, 36, a rolling shaft, a unit work piece supply unit 42, and a product discharge unit. The driving unit 30 may include a given electrical motor or a motive power. The type and shape of the driving unit are not integral parts of the present invention and well known in the art. Thus, description on them will not be given. Power from the driving unit is transferred to the first and second rollers 38, 36 via a power transmission unit, which is composed of the motor shaft, the power transmission chain 32, a power transmission shaft 56, and the power transmission gears 44, 46 and 48. The power transmission gear 44 attached to the power transmission shaft 56 is geared with the power transmission gears 48, 46 attached to the first and second rollers 38, 36 to drive the first and second rollers 38, 36. The power transmission gears 48, 46 attached to the first and second rollers 38, 36 are mounted on flat first and second roller shafts and are spaced from each other. The power transmission gear 44 connected to the power transmission shaft is geared with both the power transmission gears 48, 46 attached to the first and second rollers to drive the first and second rollers 38, 36 in the same direction, i.e., in a direction along which the unit work piece 10′ supplied from the unit work piece supply unit is transferred between the first roller 48 and a rolling shaft 34 and between the second roller 46 and the rolling shaft 34.

The first and second rollers 48, 46 come in contact with each other, and have urethane drums 38′, 36′ attached thereto, for providing the friction force and the press force, which are sufficient to transmit and roll the unit work piece 10′ introduced through the supply unit 42. In the concrete, the urethane drums 38′, 36′ exhibit an interaction force by the elasticity of the urethane drums themselves against the rolling shaft 34, which is disposed with it coming in contact with the urethane drums 38′, 36′ over a portion where the urethane drums 38′, 36′ come in contact with each other in normal times. The urethane drums 38′, 36′ feed the introduced unit work piece 10′ by means of the friction force and also give a sufficient press force to the unit work piece 10′, which is transferred and rolled between the rolling shaft 34 and the first roller 38 and between the rolling shaft 34 and the second roller 36 by means of an elastic interaction force of the urethane drums themselves, thus increasing a rolling force given to the work piece. That is, the urethane drums 38′ and 36′ not only improve the feed capability, but also increase the rolling interaction force in such a manner that it give the interaction force against the rolling shaft by means of the elastic force of the urethane drums themselves by compressing the unit work piece 10′ against the rolling shaft 34.

In a state where the elastic interaction force of the urethane drums is excluded as such, it was found that a work of rolling the elastic steel band of STS#301-EH stainless steel material according to the present invention at a desired angle, i.e., over 1.5 revolution is very difficult, although it is not impossible. Practically, it was found that an optimum rolling angle of the steel elasticity band according to the present invention, i.e., about 2 revolutions (720°) was not obtained by changing only the diameter of the steel roller except for the urethane drums, but it can be accomplished by adding the rolling force through the elasticity of urethane.

The work piece supply unit takes in the unit work piece 10′ between the urethane drum 38′ of the first roller 38 and the rolling shaft 34 with an angle of about 45°. The apparatus can be constructed to give a predetermined interaction force (for example, driving force) according to a contact force between the rolling shaft 34 and the urethane drum 38′ of the first roller, in order to take in the unit work piece 10′ and initiate the feed operation by the friction force of the urethane drum.

The interaction force between the urethane drums 38′, 36′ and the first and second rollers 38, 36 can be accomplished by interaction force control mechanisms 50, 40 for controlling the interaction force between the rolling shaft 34 and the urethane drums. In this embodiment, the rolling shaft 34 is mounted in the rolling shaft mounting block 40 and upwardly moves the rolling shaft mounting block 40 by using an interaction force control bolt 50, thus controlling the interaction force between the rolling shaft and the first and second rollers. Furthermore, a longitudinal groove is formed at the center of the rolling shaft 34. This further improves the efficiencies of the feed capability and the rolling interaction force.

The rolling amount of the unit work piece 10′ to be machined is changed according to the interaction force between the rolling shaft 34 and the urethane drums 38′, 36′, which is controlled by these interaction force mechanisms 50, 40.

The operation of the rolling apparatus according to the present invention will be described in detail as follows.

The unit work piece 10′, which is cut to have a desired shape through the press work step, is introduced between-the rolling shaft 34 and the first roller 38 through the supply unit at an angle of about 45°. For example, the driving force provided by the driving unit 30 such as an electrical motor revolves the first and second rollers 38, 36 via the power transmission chain 32 and the power transmission shaft 56. The introduced unit work piece 10′ is then rolled by the elasticity interaction force between the urethane drums and the rolling shaft, while moving between the urethane drum 38′ of the first roller and the rolling shaft 34 and between the urethane drum 36′ of the second roller 36 and the rolling shaft 34 by means of the revolution force. The rolled half-finished work piece 10′ is riding on the rolling shaft 34, pushed toward an opposite side of the supply unit 42 by means of a subsequent work and a discharged half-finished work piece 10″, and then contained in the discharge unit (container, not shown).

Two guide members (not shown) can be disposed in a width corresponding to a width of the work piece over the rolling shaft in order to maintain the half-finished work piece 10″ riding in the space over the rolling shaft 34, and assist a subsequent work and discharge of the half-finished work piece 10″.

Thereafter, the half-finished elastic steel band which is rolled about 2 revolutions (720°) are unfolded to have a shape suitable for the shape of the head through the unfolding step, as shown in FIG. 1.

In the present embodiment, it has been described that the STS#301-EH stainless steel is used as the elastic steel band material. However, the present invention is not limited thereto, but can employ any elastic steel, etc. which has the same or similar function as the STS#301-EH stainless steel.

Furthermore, in the present embodiment, it has been described that the band has the slots coupled to the mounting portion of the flexible sun cap. The slots may not be used depending on the coupling type of the flexible sun cap and the elasticity band. For example, the elastic steel band according to the present invention can be inserted into the texture elasticity band containing unit, which is integrated with the flexible sun cap visor unit, and can be coupled to the flexible sun cap visor unit. In this case, the slots can become unnecessary.

Moreover, according to the present invention, a case where the elastic steel band according to the present invention is applied to the sun cap has been described. However, the elastic steel band according to the present invention can be also applied to any hat of a similar kind.

The present invention provides the elastic steel band is combined with a flexible sun cap visor unit to provide a sun cap, which is wound over 1 revolution (360°) when the cap is not worn, and method and apparatus for manufacturing the same.

The volume of the sun cap fabricated using the elastic steel band is significantly reduced, when it is not worn, thus improving portability and keeping characteristics and reducing the distribution cost. Moreover, when the cap is not worn, the sun cap keeps completely wound over 1 revolution (360°). Therefore, there is no need for an opening unit of an elastic band element as in a conventional sun cap. Furthermore, the sun cap according to the present invention is advantageous in that it can be easily handed held, can provide beautiful appearance and can satisfy a user's preference.

Although the foregoing description has been made with reference to the preferred embodiments, it is to be understood that changes and modifications of the present invention may be made by the ordinary skilled in the art without departing from the spirit and scope of the present invention and appended claims. 

1. A method of manufacturing an elastic steel band 10 for a sun cap or a hat, comprising: a pre-work step of preparing an elastic steel band material composed of elastic steel (S100); a press work step (S200) of cutting the material (S202) into a size and shape corresponding to a flexible sun cap visor unit 22 to be assembled finally; a step of rolling the press-worked unit work piece 10′ over 1.5 revolutions (540°) to less than 3 revolutions (1080°) (S300); and a step of winding both ends of the rolled half-finished work piece 10″ in a direction opposite to the rolling direction to form unfolded units 14 (S300).
 2. The method as claimed in claim 1, wherein the pre-work step (S100) comprises the step (S104) of performing a rounding process on edges of the material to form consecutive elastic steel strips from which projections or tips are removed.
 3. The method as claimed in claim 1, wherein the press work step (S200) comprises the step (S206) of cutting both ends of the unit work piece 10′ in a round shape.
 4. The method as claimed in claim 1, wherein the press work step (S200) comprises the step (S204) of punching slots 16 into which a coupler 24 of the sun cap visor unit 22 is inserted.
 5. The method as claimed in any one of claims 1 to 4, wherein the elastic steel is STS#201-EH stainless steel.
 6. The method as claimed in any one of claims 1 to 4, wherein the rolling step (S300) includes rolling the unit work piece 10′ about 2 revolutions (720°).
 7. An apparatus for rolling a steel band for a sun cap or a hat, comprising: a driving unit 30, power transmission units 32, 56, 44, 46 and 48, first and second rollers 38, 36, a rolling shaft 34, a supply unit 42 and a discharge unit, wherein the driving unit 30 generates power and transfers the generated power to the power transmission units 32, 56, 44, 46 and 48, the power transmission units 32, 56, 44, 46 and 48 transmit the power from the driving unit 30 to the first and second rollers 38, 36, thus revolving the first and second rollers 38, 36 in the same direction, i.e., a direction where a unit work piece 10′ is feed, the first and second rollers 38, 36 include elastic drums 38′, 36′, respectively, wherein the elastic drums 38′, 36′ are mounted on the shaft with them coming in contact with each other, the rolling shaft 34 is mounted with it coming in contact with the elastic drums 38′, 36′ of the first and second rollers 38, 36 over a portion where the first and second rollers 38, 36 are brought in contact with each other, the supply unit 42 introduces the unit work piece 10′ for the elastic steel band 10 with a distance between the elastic drum 38′ of the first roller 38 and the rolling shaft 34, the unit work piece 10′ is feed between the elastic drum 36′ of the second roller 36 and the rolling shaft 34 by means of a friction force of the elastic drum 38′ of the first roller 38, during the feed, an elastic interaction force of the elastic drums 38′, 36′ of the first and second rollers 38, 36 presses the unit work piece 10′ against the rolling shaft 34, whereby the unit work piece 10′ is rolled over 1.5 revolutions (540°) to less than 3 revolutions (1080°), and a half-finished work piece 10″ for the rolled elastic steel band is discharged through a discharge unit.
 8. The apparatus as claimed in claim 7, further comprising interaction force control mechanisms 50, 40 for controlling a contact force between the rolling shaft 34 and the elastic drums 38′, 36′ of the first and second rollers 38, 36, wherein the rolling angle of the rolled half-finished work piece 10″ is changed by controlling the contact force between the rolling shaft 34 and the elastic drums 38′, 36′ of the first and second rollers 38, 36 and an interaction force accordingly.
 9. The apparatus as claimed in claim 7 or 8, wherein the elastic drums 38′, 36′ are formed using urethane.
 10. An elastic steel band, comprising: a winding unit 18 of over 1 revolution (360°) formed at the center of the elastic steel band, and unfolded units 14 formed at both ends of the elastic steel band, wherein the elastic steel band is coupled to a flexible visor unit for a sun cap or a hat, and is formed using an elastic steel material having elasticity enough to wind the flexible visor unit over 1 revolution (360°) when the sun cap or the hat is not worn.
 11. The elastic steel band as claimed in claim 10, wherein the elastic steel material is STS#301-EH stainless steel.
 12. The elastic steel band as claimed in claim 10 or 11, further comprising slots 16 into which a flexible sun cap visor unit 22 is inserted. 